The present invention relates to a light emission delay circuit for adjusting the timing of a timing light for detecting ignition timing for an automobile engine.
Efficient operation of automobile engines requires that an air-fuel mixture be ignited in a combustion chamber when the piston is closest in its compression stroke to the ignition plug, that is, when the piston reaches the top dead center (hereinafter referred to as "TDC"). In reality, however, some automobile engines ignite the air-fuel mixture just before the piston arrives at the TDC as a certain interval of time elapses before the mixture is combusted after the ignition plug has produced a spark. This type of automobile is known as an "BTDC" automobile. Other automobile engines effect ignition of an air-fuel mixture after the piston has moved past the TDC for the purpose of emission control. An automobile equipped with such engines is referred to as a "ATDC" automobile.
Ignition timing with respect to the timing with which the piston reaches the TDC is an important factor for determining the performance of an engine. Therefore, the adjustment of ignition timing is one of vital tasks in servicing automobile engines. One known ignition timing detector necessary for ignition timing adjustment is a timing light.
Known ignition timing detectors however typically have a poor resolution and a reduced degree of accuracy due to an increased delay time required for light emission by the timing light. Furthermore, a light emission delay circuit for the ignition timing detector is relatively unstable in operation and less immune to external noise.